1. Field of the Invention
The present invention relates to a dicing method for dicing a semiconductor wafer with a die attach film into chip form.
2. Description of the Related Art
One method of manufacturing electronic components comprises a laminating step of laminating an electronic component assembly consisting of a plurality of circuit patterns formed on an insulating substrate or a wafer to an adhesive sheet, a cutting/separating step (dicing step) of cutting the laminated wafer or electronic component assembly to form chips, a UV irradiation step of irradiating with UV rays from the adhesive sheet side to reduce the adhesive force of the adhesive layer, a pick up step of picking up the separately cut chips from the adhesive sheet, and a fixing step of applying an adhesive to the bottom surfaces of the picked up chips and fixing them to a lead frame or the like by means of this adhesive.
Regarding the cutting step, a method of laminating a wafer or electronic component assembly to an adhesive sheet and further fixing the adhesive sheet to a ring frame, then cutting and separating (dicing) into separate chips is known.
Methods of using an adhesive sheet (die attach film-integrated sheet) having a die attach film laminated onto an adhesive sheet used in such a manufacturing method and thus having both the function of an adhesive sheet for use in dicing and the function of an adhesive for fixing chips to a lead frame or the like have been proposed (see Patent Document 1 and Patent Document 2). The step of applying adhesive after dicing can be skipped by using a die attach film-integrated sheet for manufacturing electronic components.
Additionally, die attach film-integrated sheets excel in their ability to control the thickness of the adhesive portion and suppress excess adhesive being squeezed out as compared with methods using adhesives to bond the chips and lead frame.
However, with increased integration of semiconductor components, chip sizes have become larger and thinner, increasing cases in which the chip pick up work after dicing is difficult. Furthermore, at the time of dicing, not only the semiconductor wafer, but also the die attach film and the adhesive layer on the adhesive sheet, are diced, so that the die attach films and adhesive layers can be intermixed on the dicing line, and even after irradiation by UV rays subsequent to dicing for the purpose of reducing the adhesive force, there are cases of poor separability during pick up resulting in pick up errors.    Patent Document 1: JP 2006-049509 A    Patent Document 2: JP 2007-246633 A